This invention relates to a filter press and more particularly to a filter plate with a filter cloth hanging thereon, and a method for assembling the filter cloth onto the filter plate.
Filter presses are well known as a type of pressure filter, and is especially used for liquid-solid separation. Such presses include a series of filter plates which are compressed together between two heads. Hung over each plate is a filter cloth which covers all the filter areas. Typically, each plate includes a center hole and has channels along its surface. The sludge can enter through the center hole, pass through the spaces between the plates, and then enter the plates through the filter cloth to leave through a corner of each frame. The filtrate output passes out of the corner and is collected. As the filtrate passes through the press, a cake is formed in the spaces between adjacent plates. When the filter press is full of the solid cake material, the filtration is stopped, the plates released by releasing the pressure against the heads, sliding them apart, and the cake is removed. The filter cloth can then be removed for washing or replacement.
In the type of presses using filter plates with a center hole therein, it is necessary for the filter cloth to pass through the center hole of the plate and cover both sides of the plate. Generally, filter cloths are available as a single unit having two sides, with an interconnected center hole consisting of a tubular section. The two sides of the filter cloth are usually made of a unitary construction and is typically sewn together. To hang the filter cloth over the filter plate is a very difficult task. Usually, one side of the filter cloth is folded and compressed so that it can be squeezed through the center hole of the filter plate and is then pushed and squeezed through the center hole to the other side of the filter plate. Once on the other side of the center hole, it is again opened up to cover the other side of the filter plate. However, it is a most difficult and time consuming task, especially when it is necessary to continuously change the filter cloth for replacement or cleaning. Such constant manipulation becomes most awkward.